TR10: Peering into Video's Future

This article is one in a series of 10 stories we're running this week covering today's most significant emerging technologies. It's part of our annual "10 Emerging Technologies" report, which appears in the March/April print issue of Technology Review.

Ted Stevens, the 83-year-old senior senator from Alaska, was widely ridiculed last year for a speech in which he described the Internet as "a series of tubes." Yet clumsy as his metaphor may have been, Stevens was struggling to make a reasonable point: the tubes can get clogged. And that may happen sooner than expected, thanks to the exploding popularity of digital video.

TV shows, YouTube clips, animations, and other video applications already account for more than 60 percent of Internet traffic, says CacheLogic, a Cambridge, England, company that sells media delivery systems to content owners and Internet service providers (ISPs). "I imagine that within two years it will be 98 percent," adds Hui Zhang, a computer scientist at Carnegie Mellon University. And that will mean slower downloads for everyone.

Zhang believes help could come from an unexpected quarter: peer-to-peer (P2P) file distribution technology. Of course, there's no better playground for piracy, and millions have used P2P networks such as Gnutella, Kazaa, and BitTorrent to help themselves to copyrighted content. But Zhang thinks this black-sheep technology can be reformed and put to work helping legitimate content owners and Internet-backbone operators deliver more video without overloading the network.

For Zhang and other P2P proponents, it's all a question of architecture. Conventionally, video and other Web content gets to consumers along paths that resemble trees, with the content owners' central servers as the trunks, multiple "content distribution servers" as the branches, and consumers' PCs as the leaves. Tree architectures work well enough, but they have three key weaknesses: If one branch is cut off, all its leaves go with it. Data flows in only one direction, so the leaves'--the PCs'--capacity to upload data goes untapped. And perhaps most important, adding new PCs to the network merely increases its congestion--and the demands placed on the servers.

In P2P networks, by contrast, there are no central servers: each user's PC exchanges data with many others in an ever-shifting mesh. This means that servers and their overtaxed network connections bear less of a burden; data is instead provided by peers, saving bandwidth in the Internet's core. If one user leaves the mesh, others can easily fill the gap. And adding users actually increases a P2P network's power.

There are just two big snags keeping content distributors and their ISPs from warming to mesh architectures. First, to balance the load on individual PCs, the most advanced P2P networks, such as BitTorrent, break big files into blocks, which are scattered across many machines. To re­assemble those blocks, a computer on the network must use precious bandwidth to broadcast "metadata" describing which blocks it needs and which it already has.

i agree ... I've written some thoughts over the past few months on the p2p effect:

http://e-convergence.blogspot.com/2007/03/joost.html

http://e-convergence.blogspot.com/2007/02/these-hips-dont-lie.html

http://e-convergence.blogspot.com/2007/01/joost-it.html

http://e-convergence.blogspot.com/2006/12/moves-in-news.html

http://e-convergence.blogspot.com/2006/11/peer-tv-peer.html

2941 Days Ago

03/12/2007

P2P vs. Mesh

Please correct me if I'm wrong, but it appears that the author is conflating P2P distribution with mesh networks.

In a P2P network, the physical infrastructure still looks like a tree, but the bandwidth is more efficiently employed because underutilized branches can become content distributors as well as receivers. A P2P network does not increase the total bandwidth available, it just uses the bandwidth better.

In a mesh network, users form new infrastructure by connecting directly (and often through multiple alternate pathes), and the network no longer looks like a tree. A mesh network increases the system's total bandwidth.

Both P2P and mesh networks benefit from "network effects" (i.e., the more users, the better the network), and they are complementary approaches. However, mesh networks have a number of benefits that P2P networks do not, including increasing the resiliency of the network and reducing the control that any ISP can exert over the content distributed on the network and the cost of connection.

2940 Days Ago

03/13/2007

Very concise. I am in a 100 level intro to computers class and am supposed to review six articles this semester. My cousin is using his computer in the fashion you describe--using it to help process a project distributed among a large number of PC's. Instead of using processing space, this is only in reference to bandwidth streamlining?

2892 Days Ago

04/30/2007

I think you are wrong, but I'm not sure...

In P2P you send your payload/files/streams from anybody to anybody. Isn't that full-mesh?

The signaling doesn't really matter when it comes to bandwidth when the amount of data is big. Just implement an intelligent signaling and then wonder about how much information can be sent now. 100%?

2941 Days Ago

03/12/2007

Easy way to get more capacity

Since spam and viruses actually use about half the Internet bandwidth, why not institute the "penny a message" idea and kill them off, freeing up bandwidth for real use.

Is it perhaps because the suppliers of products and services for the Internet don't want to free up that bandwidth - it would negatively affect their sales?

Fiberman!

2941 Days Ago

03/12/2007

more than bandwidth alone ... you also need QoS, without it you can have big fat pipes ... but your video looks lost because an essential packet got 'lost' on the network

2939 Days Ago

03/14/2007

QoS

Good point.

I lived thorugh the era 15+ years ago when everybody was saying that the telco protocol ATM would take over all data transfers because it offered compatibility of data with the current voice traffic. Of course, data traffic overwhelmed voice anyway, but ATM lost to IP because 53 byte ATM packets had very poor throughput efficiency with data.

Personally, I think streaming video as IP traffic is insane! Surely others think so too - and are looking at more efficient distribution protocols for streaming video. I know the movie industry is doing work in this area for a private network in LA.

2936 Days Ago

03/17/2007

As a business development guy for a regional ISP, I can tell you we'd love to charge a penny a message and get rid of spam. But there are two basic obstacles: (a) Spammers hide who they are, so there's no reliable way to bill them (b) P2P is anonymous, so there's no reliable way to bill P2P users, either. If these new tree-mesh technologies allow identification and billing of traffic at a granular level, we'll gladly do what we can to help adoption of that tech.

2892 Days Ago

04/30/2007

"Since spam and viruses actually use about half the Internet bandwidth..."

Says who?

2905 Days Ago

04/17/2007

P2P technology is future

As you will see on TVKoo system, the global streaming with less cost is possible. One streaming server could support millions users online simultaneously with quality closer to DVD. There are changes since people could stream as easy never been.

2773 Days Ago

08/27/2007

p2p video is up and running

former founders of skype en napster have foreseen this issue and anticipated by developing the peer2peer video platform http://www.joost.com/

2772 Days Ago

08/28/2007

redundancy of discussion

im not saying i know anything but common sense shows that within the decade bandwidth is going grow in leaps. which means we shoudnt worry about junk on the net (90%) but about increasing its power and bandwidth.

2730 Days Ago

10/09/2007

P2P Video Education

Currently I'd chance to see P2P education based video based education sharing website called www.ivyse.com, currently on their beta site. This is a revolutionary idea, Peer can share their educational knowledge through this portal. Ivyse.com people also interested in bring P2P tools using dimdim utilities. Keep watching! www.ivyse.com